Safety report published for HEMS helicopter accident in November 2020

While the helicopter was damaged, the four occupants were unharmed. The Spanish Comisión de Investigación de Accidentes e Incidentes de Aviación Civil (CIAIAC) explains in its safety investigation reportthat the aircraft had departed Taulí hospital, Sabadell at 10:24 hrs on a HEMS task to attend to a casualty who had fallen three meters.

On board were the Pilot, a Technical Crew Member and two medical personnel. The pilot had 2190 hours of flying experience in total. The original intent was to land on a football pitch 300m from the casualty; however, during the flight, the medical team requested the pilot to land as close as possible.

Winds in the area were light, with speeds of between five and eight knots from a 240-degree direction. Visibility was good. The pilot replied that he would have to go around to turn into the wind. He also mentioned that there were rubbish containers and a cable in the vicinity of the patient’s home. Another option for the landing was a nearby field, but the pilot ruled it out as it was fenced off.

Rotor blade struck the aircraft cable cutter

During the landing, the HEMS technical crew member, the doctor and the nurse helped the pilot to monitor the cables, poles and the position of the rubbish containers. At 10:39 hrs, the sound of a rotor blade striking the aircraft cable cutter could be heard. Once the helicopter was fully down and the occupants confirmed they were unharmed, they decided to disembark to assess what had happened.

CIAAIC explained that the slope in the chosen area exceeded the established limits, causing one of the main rotor blades to hit the upper cable cutter when the pilot lowered the collective to settle the aircraft after touch down. The damage extended to the cable cutter system, one main rotor blade, the front left cockpit window and one skid strut.

Analysis of the Flight Data Recorder showed that the aircraft slipped backwards. When the pilot lowered the collective to settle the aircraft, one of the main rotor blades struck the helicopter’s upper cable cutter (coinciding with the extreme values of the longitudinal, lateral and vertical accelerations), and the noise of the impact can be clearly discerned in the recording from the cockpit voice recorder. The impact causes the aircraft to slip backwards again.

Earlier this year, the US National Transportation Safety Board selected the items for the agency’s 2021–2022 Most Wanted List of Transportation Safety Improvements.